The University of Florida intends to continue as a Clinical Center with its network of affiliates, satellites, and participating physicians as part of the nationally constituted diabetes trial network (Type 1 Diabetes TrialNet), in order to (1) complete the Diabetes Prevention Trial- Type 1 (DPT-1) and (2) perform novel intervention studies to preserve pancreatic beta cell function and prevent Type 1 diabetes as well as better understand the natural history and immunopathogenesis of Type 1 diabetes. The University of Florida Clinical Center (one of 9 nationwide) with its network of affiliates and satellites and participating has randomized 100 subjects (50 to each of the high and intermediate-risk arms of the DPT-1. Of the over 80,000 relatives screened in the DPT-1 to date, the University of Florida and its network have screened over 14,000, placing it among the top two centers nationally both in terms of numbers screened and randomized. Although enrolment for the high-risk arm is now closed with results expected late May 2000, screening, staging and randomization for the intermediate-risk arm is actively continuing. This Center has active participation in 6 ancillary studies, three of which originate at the University of Florida. With the completion of enrolment for the high-risk protocol, and the establishment of TrialNet (a stable, high-quality co-operative group infrastructure necessary for the conduct of effective and efficient clinical trials), we have submitted a novel clinical protocol involving the administration of DiaPep277 to high-risk autoantibody positive relatives to prevent or delay the onset of Type 1 diabetes. DiaPep277 is an immunomodulatory agent, which is immunologically cross-reactive with the native p277 peptide of human heat shock protein 60. The active ingredient of DiaPep277 is a 24 amino acid peptide (Po-102), having the sequence of p277, in which two cysteine residues have been substituted by valine. It has been shown to prevent diabetes in animal models (NOD, streptozotocin-induced) of Type 1 diabetes. Extensive studies in mice and Phase 1 human studies have shown it to be safe. Preliminary phase 2 clinical trials in new-onset patients with diabetes reveal preservation of c-peptide and the need for lower insulin doses compared to placebo in achieving comparable metabolic control. It is thus a promising agent to consider for the prevention of Type 1 diabetes.